The invention provides a dispersion of zirconium oxide having a content as high as 20% by weight or more, but a low viscosity, and having a high transparency, which has a transmittance of 35% or more at a wave length of 400 nm, a transmittance of 95% or more at a wave length of 800 nm, and a viscosity of 20 mPa·s or less at a temperature of 25° C. Such a dispersion of zirconium oxide can be obtained by reacting a zirconium salt with an alkali in water to obtain a slurry of particles of zirconium oxide; filtering, washing, and repulping the slurry; adding an organic acid to the resulting slurry in an amount of one mole part or more per mole part of the zirconium in the slurry; hydrothermally treating the slurry at a temperature of 170° C. or higher; and washing and concentrating the resulting aqueous dispersion of particles of zirconium oxide.